An aerosol gas deposition technique is a deposition method of converting fine particles or powders placed in an aerosol-generating container as a source material to aerosol by agitation with a carrier gas, and transporting the aerosol as the gas stream under the pressure difference between the aerosol-generating container and the deposition chamber and thus, making it collide with a substrate to synthesize a thin film on it. In the method, fine particles are accelerated to high speed on the substrate, and their kinetic energy is locally converted to heat energy on the substrate. Because the substrate heating occurs only locally, the substrate is hardly affected by the heat (normal-temperature deposition) and the deposition rate is higher than that of other deposition methods. For that reason, a film having high-density and high-adhesiveness can be generally formed.
It is considered that the optimal mean diameter of fine particles applicable for the aerosol gas deposition technique is generally about 0.5 μm. The film formation by such deposition method is performed by using the powder whose particle size close to such size condition. On the other hand, in the case where the particle diameter of such fine particles is larger than this, it is considered that the density or adhesiveness of the film is further increased. However, it has been difficult to form a film steadily.
On the other hand, the following Patent Document 1 discloses a method of converting fine particles whose surface is activated by plasma irradiation or microwave irradiation into aerosol and spraying such fine particles on a substrate. As described above, by applying some kind of energy to fine particles in question, it is possible to get rid of the existence of an inert surface caused by adsorption of any impurities on the surfaces of such fine particles or the like. Accordingly, it is possible to facilitate the formation of a construction.
Moreover, Patent Document 2 discloses an aerosol deposition apparatus including a means for ionizing an aerosol and a means for applying bias voltage opposite in polarity to that of the ion of the aerosol to a substrate. As the means for ionizing an aerosol, a high-voltage apparatus forming a non-uniform electric field, or a magnetron is exemplified. With the above-mentioned configuration, an aerosol having a predetermined concentration collides with a substrate. As a result, it is possible to deposit more fine particles on the substrate.    Patent Document 1: Japanese Patent Application Laid-open No. 2005-36255    Patent Document 2: Japanese Patent Application Laid-open No. 2005-290462